Use boulder error messages.

acme/error.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"strings"
 )
 
 const (
@@ -28,6 +29,27 @@ type TOSError struct {
 	RemoteError
 }
 
+type domainError struct {
+	Domain string
+	Error  error
+}
+
+type challengeError struct {
+	RemoteError
+	records []validationRecord
+}
+
+func (c challengeError) Error() string {
+
+	var errStr string
+	for _, validation := range c.records {
+		errStr = errStr + fmt.Sprintf("\tValidation for %s:%s\n\tResolved to:\n\t\t%s\n\tUsed: %s\n\n", 
+		validation.Hostname, validation.Port, strings.Join(validation.ResolvedAddresses, "\n\t\t"), validation.UsedAddress)
+	}
+
+	return fmt.Sprintf("%s\nError Detail:\n%s", c.RemoteError.Error(), errStr)
+}
+
 func handleHTTPError(resp *http.Response) error {
 	var errorDetail RemoteError
 	decoder := json.NewDecoder(resp.Body)
@@ -46,7 +68,6 @@ func handleHTTPError(resp *http.Response) error {
 	return errorDetail
 }
 
-type domainError struct {
-	Domain string
-	Error  error
+func handleChallengeError(chlng challenge) error {
+	return challengeError{chlng.Error, chlng.ValidationRecords}
 }

acme/http_challenge.go

@@ -80,7 +80,7 @@ Loop:
 		case "pending":
 			break
 		case "invalid":
-			return errors.New("The server could not validate our request.")
+			return handleChallengeError(challengeResponse)
 		default:
 			return errors.New("The server returned an unexpected state.")
 		}

acme/messages.go

@@ -72,15 +72,25 @@ type identifier struct {
 	Value string `json:"value"`
 }
 
+type validationRecord struct {
+	URI               string   `json:"url,omitempty"`
+	Hostname          string   `json:"hostname,omitempty"`
+	Port              string   `json:"port,omitempty"`
+	ResolvedAddresses []string `json:"addressesResolved,omitempty"`
+	UsedAddress       string   `json:"addressUsed,omitempty"`
+}
+
 type challenge struct {
-	Resource         string `json:"resource,omitempty"`
-	Type             string `json:"type,omitempty"`
-	Status           string `json:"status,omitempty"`
-	URI              string `json:"uri,omitempty"`
-	Token            string `json:"token,omitempty"`
-	KeyAuthorization string `json:"keyAuthorization,omitempty"`
-	TLS              bool   `json:"tls,omitempty"`
-	Iterations       int    `json:"n,omitempty"`
+	Resource          string             `json:"resource,omitempty"`
+	Type              string             `json:"type,omitempty"`
+	Status            string             `json:"status,omitempty"`
+	URI               string             `json:"uri,omitempty"`
+	Token             string             `json:"token,omitempty"`
+	KeyAuthorization  string             `json:"keyAuthorization,omitempty"`
+	TLS               bool               `json:"tls,omitempty"`
+	Iterations        int                `json:"n,omitempty"`
+	Error             RemoteError        `json:"error,omitempty"`
+	ValidationRecords []validationRecord `json:"validationRecord,omitempty"`
 }
 
 type csrMessage struct {

acme/tls_sni_challenge.go

@@ -90,7 +90,7 @@ Loop:
 		case "pending":
 			break
 		case "invalid":
-			return errors.New("The server could not validate our request.")
+			return handleChallengeError(challengeResponse)
 		default:
 			return errors.New("The server returned an unexpected state.")
 		}